The chords indicated are the chords of the song in order, they're shown with the lyrics to give you a rough idea of the timing but you'll have to use your ears to get it accurate. Whether the ones tabbed are the exact fingerings used as played in the original varies from tab to tab.

As for what you're supposed to play... that's up to you. You could just play the guitar part, maybe some chord-melody version of it, sing and play it, play it with a full band, whatever you want.

R.I.P. My Signature. Lost to us in the great Signature Massacre of 2014.